package com.lagou.mr.homework1;

import com.lagou.mr.wc.WordCountDriver;
import com.lagou.mr.wc.WordCountMapper;
import com.lagou.mr.wc.WordCountReducer;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import java.io.IOException;

public class HomeWorkDriver {
    public static void main(String[] args) throws IOException, ClassNotFoundException, InterruptedException {
        //1. 获取配置文件对象，获取job对象实例
        final Configuration conf = new Configuration();
        Job job = Job.getInstance( conf, "HomeWorkDriver" );
//            2. 指定程序jar的本地路径
        job.setJarByClass( HomeWorkDriver.class );
//            3. 指定Mapper/Reducer类
        job.setMapperClass( HomeWorkMapper.class );
        job.setReducerClass(HomeWorkReducer.class );
//            4. 指定Mapper输出的kv数据类型
        job.setMapOutputKeyClass( NumberBean.class );
        job.setMapOutputValueClass( NullWritable.class );
//            5. 指定终输出的kv数据类型
        job.setOutputKeyClass( NumberBean.class );
        job.setMapOutputValueClass( NullWritable.class );
//            6. 指定job处理的原始数据路径
        FileInputFormat.setInputPaths( job,new Path( args[0] ) );
//            7. 指定job输出结果路径
        FileOutputFormat.setOutputPath( job,new Path( args[1] ));
//            8. 提交作业
        boolean flag = job.waitForCompletion( true );
//            jvm退出：正常退出0，非0值错误推出
        System.exit( flag?0:1 );
    }
}
